Spatially resolved evidence of the impact of quasar driven outflows on recent star formation : The case of Mrk 34

TL;DR

This study uses spatially resolved data to show that quasar-driven outflows in Mrk 34 can both trigger star formation at their edges and prevent it in more disrupted regions, revealing complex feedback effects.

Contribution

It provides the first spatially resolved evidence of both positive and preventive feedback from quasar outflows on star formation in Mrk 34.

Findings

Outflows correlate with enhanced young stellar populations at their edges.

Disrupted gas regions show no star formation enhancement.

Quasar outflows can both trigger and suppress star formation.

Abstract

We present the results of our spatially resolved investigation into the interplay between the ages of the stellar populations and the kinematics of the warm ionised outflows in the well-studied type II quasar Markarian 34. Utilising IFS data, we determine the spatial distribution of the young stellar population (YSP; $t_{ysp} < 100 \mbox{ Myr}$) using spectral synthesis modelling. We also employ the $\mbox{[OIII]}\lambda 5007$ emission line as a tracer of the warm ionised gas kinematics. We demonstrate a spatial correlation between the outer edges of the blue-side of the outflow and an enhancement in the proportion of the YSP flux, suggesting that the outflow is responsible for triggering star formation in this region. In regions with more highly disrupted gas kinematics, we find that the proportion of YSP flux is consistent with that found outside the outflow region, suggesting that the increased disruption is preventing a similar enhancement in star formation from occurring. Our analysis suggests that Mrk 34 is an example of quasar driven outflows simultaneously producing both `positive' and `preventive' feedback, further demonstrating the complex nature of the relationship between quasars and their host galaxies.